ctf-skills is a collection of agent instructions for solving capture-the-flag security challenges, including web exploitation, binary vulnerabilities, cryptography, reverse engineering, forensics, and OSINT. It is intended for agents and people working through CTF problems, and its skills can be loaded into supported coding-agent workflows.
Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/ljagiello/ctf-skillsnpx agentmods add skills/ljagiello/ctf-skills/solve-challengeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ljagiello/ctf-skills/solve-challenge)<a href="https://agentmods.dev/skills/ljagiello/ctf-skills/solve-challenge"><img src="https://agentmods.dev/badge/skills/ljagiello/ctf-skills/solve-challenge/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/ljagiello/ctf-skills/solve-challenge"><img src="https://agentmods.dev/badge/skills/ljagiello/ctf-skills/solve-challenge.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket warn
- Snyk fail
- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Privilege Escalation · line 57 Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
- high YARA Match · line 182 YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00102 | $0.02211 |
| Opus 5 | $0.00051 | $0.01105 |
| Sonnet 5 | $0.00020 | $0.00442 |
| Haiku 4.5 | $0.00010 | $0.00221 |
Grade A, and why
solve-challenge scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 13d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -s "$CTF_URL/api/v1/" | head -5 Copies of this mod
1 near-identical copy found in the catalogue:
- solve-challenge — 97% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 191 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CTF Challenge Solver
You're a skilled CTF player. Your goal is to solve the challenge and find the flag.
Environment Setup
Two setup strategies depending on your workflow:
Pre-install (recommended before competitions)
Use the central installer entrypoint:
bash scripts/install_ctf_tools.sh all
Run a narrower mode when you only want one tool group:
bash scripts/install_ctf_tools.sh python
bash scripts/install_ctf_tools.sh apt
bash scripts/install_ctf_tools.sh brew
bash scripts/install_ctf_tools.sh gems
bash scripts/install_ctf_tools.sh go
bash scripts/install_ctf_tools.sh manual
The full package lists now live in scripts/install_ctf_tools.sh.
On-demand (during challenges)
Each category skill's SKILL.md has a Prerequisites section listing only the tools needed for that category. Install as you go.
Workflow
Step 0: CTFd Platform Detection
If the CTF platform URL is known, check if it runs CTFd and switch to API-driven navigation:
# Detect CTFd (look for /api/v1/ and /themes/core/)
curl -s "$CTF_URL/api/v1/" | head -5
curl -s "$CTF_URL" | grep -oE '/themes/core/'
If CTFd is detected, ask the user for their API token (generated from CTFd Settings > Access Tokens). The token is not provided by default — the user must create one in the CTFd web UI first. Once provided, set the environment variables and proceed via API:
export CTF_URL="https://ctf.example.com"
export CTF_TOKEN="ctfd_..." # Ask user for this
Invoke /ctf-misc and load its ctfd-navigation.md for the full API reference and Python client class.
Step 1: Recon
- Explore files -- List the challenge directory, run
file *on everything - Triage binaries --
strings,xxd | head,binwalk,checksecon binaries - Fetch links -- If the challenge mentions URLs, fetch them FIRST for context
- Connect -- Try remote services (
nc) to understand what they expect - Read hints -- Challenge descriptions, filenames, and comments often contain clues
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 13d ago First seen · 191 lines · 102 tokens per session scan A 3001bc2e33ec
solve-challenge is a skill published in the GitHub repository ljagiello/ctf-skills (3,252 stars, last pushed 18d ago), licensed MIT. It adds 102 tokens to every session and 2,211 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
xiaohongshu-search-full
Search Xiaohongshu (XHS / RedNote) notes by keyword with full field extraction including body text, topics/tags, image list URLs, video stream URL, publish timestamp, and all engagement stats (likes, collects, comments, shares). Supports all page filter options: sort order (general, latest, most liked, most commented…
x-tweet-by-conversation
Collects every tweet in an X (Twitter) conversation thread given a conversation id (root tweet id) — the focal tweet plus all replies, sub-replies, and quote chains — and returns normalized per-tweet data with text, author, engagement counts, media, hashtags, mentions, inreplyto mapping, and cursor for pagination. Use…
amazon-reviews-api-skill
This skill helps users automatically extract Amazon product reviews via the Amazon Reviews API. Agent should proactively apply this skill when users express needs like getting reviews for Amazon product with ASIN B07TS6R1SF, analyzing customer feedback for a specific Amazon item, getting ratings and comments for a…
amazon-competitor-analyzer
Scrapes Amazon product data from ASINs using browseract.com automation API and performs surgical competitive analysis. Compares specifications, pricing, review quality, and visual strategies to identify competitor moats and vulnerabilities.
create-site
Creates a new Power Pages code site (SPA) using React, Angular, Vue, or Astro. Guides through the full process from initial concept to deployed site: requirements discovery, scaffolding, component planning, design, implementation, validation, and deployment. Use when the user wants to create, build, or scaffold a new…
add-cloud-flow
Integrates Power Automate cloud flows into a Power Pages site. Lists available flows, suggests relevant ones based on intent, identifies scenarios and web roles, creates metadata files, and generates client-side code to call flows. Handles both new flow registration and adding already-registered flows to additional…